A need exists for an improved means of dispensing particulate food products or ingredients from their containers. Many spices, for example, are commonly supplied in jars with screw-on caps. In the absence of a dispensing feature on the cap, it must be unscrewed and removed to enable insertion of a measuring spoon for removal of the amount desired. This procedure is inconvenient, particularly where several spices are required for use in a given recipe, and it is difficult to level off the contents of the spoon in a precise manner without spilling some of the contents. These problems can be avoided by use of a cap that has a built-in metering and dispensing rotor disposed across the mouth of the jar. Such a dispensing cap may be operated by holding the jar upside down and turning the rotor, whereby the quantity that fills the cavity in the rotor is dispensed downward by gravity when the cavity is aligned with an external aperture.
Various types of dispensing devices, including metering dispenser caps, are disclosed in prior art patents. U.S. Pat. No. 4,162,751, issued July 31, 1979, to Hetland et al., discloses a dispenser cap including a housing defining a vertically extending discharge spout and having an inlet opening and an outlet opening with a rotor disposed across the spout between the openings. The rotor has a single, axially disposed chamber that is movable from a loading position to a dispensing position upon rotation. The chamber in this device is adjustable in volume by means of a rack-and-pinion actuated member that varies the location of the chamber bottom or by means of movable segments making up the sides of the chamber. U.S. Pat. No. 3,122,278, issued Feb. 25, 1964, to Crozier, also discloses a dispenser with a metering rotor disposed across the opening of a dispensing spout, the rotor having only one measured cavity that is adjustable by insertion or removal of reducer elements. Other approaches are shown by U.S. Pat. Nos. 4,674,660, issued June 23, 1987, to Botto; 4,071,171, issued Jan. 31, 1978, to Bassignani; 3,130,874, issued Apr. 28, 1964, to Bulmer; 3,018,924, issued Jan. 30, 1962, to Reed; and 2,710,118, issued June 7, 1955, to Stoddard. These patents do not disclose a dispenser having a metering rotor disposed on an axis across the mouth or spout of a container but rather make use of elements that are movable on the same axis as the mouth of the container or employ plungers and tabs to actuate compartments of varying sizes. A dispenser that has a horizontal mounted shaft provided with spaced-apart blades operating on a shaft spanning a dispenser opening is shown in U.S. Pat. No. 2,740,562, issued Apr. 3, 1956, to Bello. This patent, however, is not concerned with dispensing a measured volume but with agitating the material being dispensed, and the rotary valve moves only within limits defined by stop pins.
To obtain maximum convenience, a dispenser cap for spices and other particulate food products should provide for delivery of precisely measured amounts directly into a mixing bowl or the like merely by the simple act of turning a knob, without requiring any adjustment to the dispenser mechanism for different amounts.